Self-balancing two-wheeled vehicle

ABSTRACT

In an aspect, a self-balancing two-wheeled vehicle is provided, having a body, and first and second wheels rotatably coupled to the body. The second wheel has at least one lateral roller rotatable about an axis that is one of oblique and orthogonal to a rotation axis of the second wheel. At least one motor is coupled to the second wheel to control rotation of the second wheel and the at least one lateral roller. At least one sensor is coupled to the body to generate orientation data therefor. A control module is coupled to the at least one motor to control operation thereof at least partially based on the orientation data generated by the at least one sensor.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 62/614,474 filed Jan. 7, 2018, the contents ofwhich are incorporated herein in their entirety.

FIELD

The specification relates generally to two-wheeled vehicles. Inparticular, the following relates to a self-balancing two-wheeledvehicle.

BACKGROUND OF THE DISCLOSURE

Toy vehicles are constructed to entertain both young and old children.The toy vehicles are intended to simulate the motion of actualreal-world vehicles, such as cars, motorcycles, etc. In the case oftraditionally two-wheeled vehicles, such as motorcycles, however,additional “training” wheels are generally provided to enable thetwo-wheeled vehicles to maintain their balance in an upright position.In some cases, these toy vehicles are remotely controlled via either aremote controller or an application executing on a mobile device thatcommunicates with the toy vehicle either tethered or wirelessly toenable a person to modify the behavior of the toy vehicle. While suchtoy vehicles simulate basic movements of their real world counterparts,the expectations of users have been heightened as a result of theeffects in modern movies and simulation games, such as auto racinggames.

SUMMARY OF THE DISCLOSURE

In one aspect, there is provided a self-balancing two-wheeled vehicle,comprising a body, a first wheel rotatably coupled to the body, a secondwheel rotatably coupled to the body, the second wheel having at leastone lateral roller rotatable about an axis that is one of oblique andorthogonal to a rotation axis of the second wheel, the self-balancingtwo-wheeled vehicle further comprising at least one motor coupled to thesecond wheel to control rotation of the second wheel and the at leastone lateral roller, at least one sensor coupled to the body to generateorientation data therefor, and a control module coupled to the at leastone sensor and the at least one motor to control operation thereof atleast partially based on the orientation data generated by the at leastone sensor.

The second wheel can have a first drive interface and a second driveinterface to which the at least one motor is coupled, and the firstdrive interface can be rotatable independent of the second driveinterface. A first of the at least one motor can be coupled to the firstdrive interface and a second of the at least one motor can be coupled tothe second drive interface. The second wheel can have a plurality oflateral rollers. Rotation of the lateral rollers can be at leastpartially based on a difference in angular velocity of the first driveinterface and the second drive interface. Each lateral roller can berotated by a transmission translation member engaged by at least onegear, each of the at least one gear being rotated via one of the firstdrive interface and the second drive interface. A first of the at leastone gear can be rotated via the first drive interface and a second ofthe at least one gear can be rotated via the second drive interface.

The first drive interface can fully control rotation of the rear wheelabout a rear axle.

The at least one sensor can include an accelerometer that generatesacceleration data, and the control module can control operation of theat least one motor at least partially based on the accelerometer datareceived from the accelerometer.

The self-balancing two-wheeled vehicle can further comprise a receivercoupled to the control module to communicate operational commandsreceived from a remote control unit to the control module, the remotecontrol unit having a set of user controls and communicating theoperational commands generated by actuation of the user controls, thecontrol module controlling the at least one motor at least partiallybased on the operational commands. The control module can at leastpartially control the at least one motor to maintain a center-of-gravityof the self-balancing two-wheeled vehicle over an area of contact of thefirst wheel and the second wheel with a travel surface. The first wheelcan be pivotable relative to the body, and pivoting of the first wheelcan be controlled by the control module at least partially based on theoperational commands received from the remote control unit. Pivoting ofthe first wheel can be at least partially controlled by the controlmodule to maintain the center-of-gravity of the self-balancingtwo-wheeled vehicle over the area of contact of the first wheel and thesecond wheel with the travel surface.

The operational commands can include a wheelie command, and the remotecontrol unit, upon receiving the wheelie command from the remote controlunit, can control the second wheel to accelerate in a first directionaway from the first wheel and immediately subsequently accelerate in asecond direction towards the front wheel to reorient the self-balancingtwo-wheeled vehicle so that the center-of-gravity of the self-balancingtwo-wheeled vehicle is over the area of contact of the second wheel withthe travel surface, wherein the control module controls the at least onemotor at least partially to maintain the center-of-gravity of theself-balancing two-wheeled vehicle is over the area of contact of thesecond wheel with the travel surface.

BRIEF DESCRIPTIONS OF THE DRAWINGS

For a better understanding of the various embodiments described hereinand to show more clearly how they may be carried into effect, referencewill now be made, by way of example only, to the accompanying drawingsin which:

FIG. 1 shows a toy motorcycle having a composite wheel in accordancewith one embodiment thereof;

FIG. 2 is a partially disassembled view of a rear portion of the toymotorcycle of FIG. 1;

FIG. 3 is a perspective view of the partially disassembled compositewheel shown in FIG. 1;

FIG. 4 shows a drive assembly coupled to gears driving a plurality ofperipheral translation assemblies of the composite wheel of FIG. 3;

FIG. 5 is a rear section view of the rear portion of the toy motorcycleof FIG. 2 illustrating various components of the composite wheel;

FIG. 6 is a top section view of the rear portion of the toy motorcycleof FIG. 2 illustrating various components of the composite wheel;

FIG. 7 shows the toy motorcycle on a travel surface;

FIG. 8 is a schematic diagram showing various electronic components ofthe toy motorcycle of FIGS. 1 to 7;

FIG. 9 shows a steering assembly of the toy motorcycle of FIGS. 1 to 7;

FIG. 10 shows the joystick of the remote control unit of FIG. 8 anddirectional regions to which the joystick can be moved;

FIGS. 11A to 11D are rear views of the rear wheel of the toy motorcycleof FIGS. 1 to 7 showing operation of the rear wheel when the joystick ismoved to the different directional regions shown in FIG. 10;

FIG. 12 shows a winding travel path of the toy motorcycle of FIGS. 1 to7;

FIG. 13 shows a rotational travel path of the toy motorcycle of FIGS. 1to 7;

FIG. 14 shows the toy motorcycle of FIGS. 1 to 7 in a drifting drivingorientation;

FIG. 15 shows the toy motorcycle of FIGS. 1 to 7 being operated tobalance on the rear wheel;

FIG. 16 is a top sectional view of a rear wheel of a toy motorcycle inaccordance with another embodiment; and

FIG. 17 is a top sectional view of the rear wheel and rear wheel supportof the toy motorcycle of FIG. 16 showing the drive arrangements drivingthe rear wheel.

DETAILED DESCRIPTION

For simplicity and clarity of illustration, where consideredappropriate, reference numerals may be repeated among the Figures toindicate corresponding or analogous elements. In addition, numerousspecific details are set forth in order to provide a thoroughunderstanding of the embodiments described herein. However, it will beunderstood by those of ordinary skill in the art that the embodimentsdescribed herein may be practiced without these specific details. Inother instances, well-known methods, procedures and components have notbeen described in detail so as not to obscure the embodiments describedherein. Also, the description is not to be considered as limiting thescope of the embodiments described herein.

Various terms used throughout the present description may be read andunderstood as follows, unless the context indicates otherwise: “or” asused throughout is inclusive, as though written “and/or”; singulararticles and pronouns as used throughout include their plural forms, andvice versa; similarly, gendered pronouns include their counterpartpronouns so that pronouns should not be understood as limiting anythingdescribed herein to use, implementation, performance, etc. by a singlegender; “exemplary” should be understood as “illustrative” or“exemplifying” and not necessarily as “preferred” over otherembodiments. Further definitions for terms may be set out herein; thesemay apply to prior and subsequent instances of those terms, as will beunderstood from a reading of the present description.

Any module, unit, component, server, computer, terminal, engine ordevice exemplified herein that executes instructions may include orotherwise have access to computer readable media such as storage media,computer storage media, or data storage devices (removable and/ornon-removable) such as, for example, magnetic disks, optical disks, ortape. Computer storage media may include volatile and non-volatile,removable and non-removable media implemented in any method ortechnology for storage of information, such as computer readableinstructions, data structures, program modules, or other data. Examplesof computer storage media include RAM, ROM, EEPROM, flash memory orother memory technology, CD-ROM, digital versatile disks (DVD) or otheroptical storage, magnetic cassettes, magnetic tape, magnetic diskstorage or other magnetic storage devices, or any other medium which canbe used to store the desired information and which can be accessed by anapplication, module, or both. Any such computer storage media may bepart of the device or accessible or connectable thereto. Further, unlessthe context clearly indicates otherwise, any processor or controller setout herein may be implemented as a singular processor or as a pluralityof processors. The plurality of processors may be arrayed ordistributed, and any processing function referred to herein may becarried out by one or by a plurality of processors, even though a singleprocessor may be exemplified. Any method, application or module hereindescribed may be implemented using computer readable/executableinstructions that may be stored or otherwise held by such computerreadable media and executed by the one or more processors.

A self-balancing two-wheeled vehicle is provided. A two-wheeled vehicleis any type of vehicle having two wheels as its only means of groundcontact during normal operation for travel over and resting on a travelsurface, such as, for example, a floor, a road, a dirt path, etc. Thetwo wheels are at least sometimes “in line”; that is, they often share acommon plane. Examples of two-wheeled vehicles include bicycles andmotorcycles whose front wheels, when oriented for travel in a straightline, share a common plane with their rear wheels.

The two-wheeled vehicle has a body, and first and second wheelsrotatably coupled to the body. The second wheel has at least one lateralroller rotatable about an axis that is one of oblique and orthogonal toa rotation axis of the second wheel. At least one motor is coupled tothe second wheel to control rotation of the second wheel and the atleast one lateral roller. At least one sensor is coupled to the controlmodule and generates orientation data. A control module is coupled tothe at least one motor to control operation thereof at least partiallybased on the orientation data generated by the at least one sensor.

By controlling rotation of the second wheel and the at least one lateralroller at least partially based on the orientation data generated by theat least one sensor, the upright orientation of the two-wheeled vehiclecan be maintained where a two-wheeled vehicle would otherwise normallybe unable to maintain its balance in an upright position (that is, withonly its two wheels contacting a travel surface).

Further, various maneuvers can be carried out by the two-wheeledvehicle. For example, the two-wheeled vehicle can simulate a “drifting”motion, wherein the rear wheel can appear to be travelling along a paththat is not normal to the rotation axis thereof. Still further, thetwo-wheeled vehicle can be configured to perform a “wheelie”, whereinthe two-wheeled vehicle is reoriented so that the two-wheeled vehiclebalances itself on its rear wheel.

FIG. 1 shows a self-balancing two-wheeled vehicle in accordance with anembodiment. The self-balancing two-wheeled vehicle is a toy motorcycle20 that has a front wheel 28 that is coupled to the body 24 via a frontwheel support in the form of a set of forks 32. The front wheel 28freely rotates about an axle 36 that is held between the forks 32. Theforks 32 are secured in a fixed position and orientation to the body 24of the toy motorcycle 20. A rear wheel 40 is rotatably coupled to a rearwheel support 44 that extends from the body 24. A rider figurine 48 ispositioned atop of the body 24 in a riding position, clutching at thehandlebars that are connected to the forks 32 as if to steer the toymotorcycle 20.

FIG. 2 shows a drive arrangement 52 within the rear wheel support 44after removal of a rear wheel support cover 46. The drive arrangement 52includes a first rear wheel control motor 56 a (which may, forsimplicity, be referred to as a first motor 56 a), which has a drivegear 60 that engages a first of four intermediate drive gears 64 a to 64d that are coupled together to transmit torque from the first motor 56 ato a first (left) side of the rear wheel 40. The fourth intermediatedrive gear 64 d is rotatably mounted on a rear axle 68. The drivearrangement 52 also includes a second rear wheel control motor 56 b(which may, for simplicity, be referred to as a second motor 56 b),which drives another set of intermediate drive gears coupled together totransmit torque from the second motor 56 b to a second (right) side ofthe rear wheel 40. The first and second motors 56 a, 56 b arebattery-powered electric motors as will be described below. While, inthe illustrated embodiment, each side employs four intermediate drivegears, other drive arrangements with other numbers of drive gears can beemployed in alternative embodiments. In a further embodiment, the motorscan be coupled directly to the sides of the rear wheel.

The construction of the rear wheel 40 and its operation in conjunctionwith the drive arrangement 52 will now be described in relation to FIGS.2 to 6. The rear wheel 40 is a composite wheel as at least somecomponents thereof do not simply rotate about a rotation axis RA of therear wheel 40, but move in other manners, as will be described. Thefourth intermediate drive gear 64 d has a wheel-engaging projection 66with a rectangular profile that extends towards the rear wheel 40. Thewheel-engaging projection 66 is received within a similarly profiledrecess 72 of a drive interface in the form of a projection bracket 76extending outwardly from a first (left) gear disk 80 a that is alsorotatably mounted on the rear axle 68. The wheel-engaging projection 66engages the interior sides of the recess 72 of the projection bracket 76such that rotation of the fourth intermediate drive gear 64 d causes thefirst gear disk 80 a to rotate. Any other suitable configurations fortransferring torque from the drive arrangements to the first gear disk80 a can be employed. The first gear disk 80 a acts as a gear and has atoothed gear face 84 a extending inwardly along a circular peripherythereof.

A second gear disk 80 b has a drive interface in the form of aprojection bracket 76 that is similarly engaged by the wheel-engagingprojection 66 of a fourth intermediate drive gear 64 h of a second setof intermediate drive gears 64 e to 64 h. Both the second gear disk 80 band the fourth intermediate drive gear 64 h are rotatably mounted on therear axle 68. The second gear disk 80 b acts as a gear and has a toothedgear face 84 b extending inwardly along a circular periphery thereofsimilar to the gear face 84 a of the first gear disk 80 a.

The drive interfaces enable the motors 56 a, 56 b to control operationof the rear wheel 40. In this particular embodiment, the driveinterfaces enable the motors 56 a, 56 b to control operation of the geardisks 80 a, 80 b which control operation of the rear wheel 40 as isdescribed herein. While, in the illustrated and described embodimentshere, the drive interfaces are non-round drive recesses, any othersuitable feature(s) for enabling the motors 56 a, 56 b to controloperation of the rear wheel 40 can be employed, such as a set of one ormore projections, a set of two or more recesses, or a combination ofrecesses and projections.

In an alternative embodiment, a single motor can be employed and use avariable transmission to provide different torque to each of the geardisks 80 a, 80 b in place of the two motors.

Positioned intermediate the first gear disk 80 a and the second geardisk 80 b is a support frame made from a first support frame portion 88a and a second support frame portion 88 b. The support frame is freelyrotatably mounted on the rear axle 68. The support frame portions 88 a,88 b define eight recesses. A transmission translation member 96 isfreely rotatably mounted within each of the recesses of the supportframe. Each transmission translation member 96 has a frustoconical gear100 that is dimensioned to fit between and engage the gear faces 84 a,84 b of the first and second gear disks 80 a, 80 b. A roller controlelement in the form of a peripheral gear face 104 is coupled to thefrustoconical gear 100 via a neck 108 that is freely rotatably securedbetween the support frame portions 88 a, 88 b. The transmissiontranslation members 96 are mounted within the recesses of the supportframe so that they rotate around axes that are perpendicular to therotation axis RA of the rear wheel 40, but do not intersect it. In somealternative embodiments, the transmission translation members 96 can bemounted so that they rotate about axes that are radial relative to therotation axis RA of the rear wheel 40. In some alternative embodiments,the transmission translation members 96 can be mounted on axles of asupport frame that are perpendicular to the rotation axis RA of the rearwheel 40.

Two wheel shell portions 116 are secured to the support frame portions88 a, 88 b and are freely rotatably mounted on the cylindrical exteriorof the projection brackets 76 of the gear disks 80 a, 80 b. The twowheel shell portions 116 mate together to form a wheel shell. The wheelshell portions 116 have a structure therein to rotatably support eightaxles 124 that are aligned with corresponding apertures in the shellformed by the shell portions 116. A roller hub 125 is mounted on eachaxle 124. Each roller hub 125 has a roller gear face 140 that mesheswith the peripheral gear face 104 of a corresponding transmissiontranslation member 96. Rotation of the transmission translation members96 is translated into rotation of the roller hub 125 via engagement ofthe peripheral gear face 104 with the roller gear face 140. Two rollersupports 128 are mounted on the roller hubs 125 and a lateral roller 132is positioned over each of the roller supports 128. The lateral rollers132 rotate about a central axis RRA of the axles 124 that is orthogonalto the rotational axis RA of the gear disks 80 a, 80 b. In alternativeembodiments, the lateral rollers can be designed to rotate about axesthat are oblique to the rotational axis RA of the gear disks. Thelateral rollers 132 have an exterior surface 136 with an arcuateprofile, and are preferably made from a soft, grippy material, such asrubber or polyurethane. The arrangement of the lateral rollers 132protruding through the shell apertures 126 and the arcuate profile ofthe exterior surfaces 136 are such that the arcuate profiles define agenerally circular outer profile of the rear wheel 40.

A side cover plate 144 covers an open side of each wheel shell portion116.

Operation of the rear wheel 40 is controlled by the motors 56 a, 56 b,which act to drive rotation of the first and second gear disks 80 a, 80b independent of one another. The motor 56 a transfers torque to thefirst gear disk 80 a via the intermediate drive gears 64 a to 64 d, thuscontrolling its rotation relative to the body 24 of the toy motorcycle20. Similarly, the motor 56 b transfers torque to the second gear disk80 a via the intermediate drive gears 64 e to 64 h, thus controlling itsrotation relative to the body 24. The gear disks 80 a, 80 b are rotatedabout the rear axle 68 and thus the rotation axis RA that is coaxial tothe rear axle 68. As each gear disk 80 a, 80 b rotates, its respectivegear face 84 a, 84 b urges the teeth of the frustoconical gears 100 ofthe transmission translation members 96 to move in the same angulardirection.

In order to cause the rear wheel 40 to act as a conventional wheel, themotors 56 a, 56 b are operated to rotate the first gear disk 80 a andthe second disk gear 80 b at the same angular velocity (that is, withthe same angular speed and direction) about the rear axle 68. As thegear faces 84 a, 84 b of the gear disks 80 a, 80 b are simultaneouslyrotated at the same angular velocity, they engage the teeth of thefrustoconical gears 100 of the transmission translation members 96,trapping the frustoconical gears 100 between them. The transmissiontranslation members 96 freely rotate within the recesses between thesupport frame portions 88 a, 88 b, which is freely rotatable about therear axle 68. The trapped frustoconical gears 100 of the transmissiontranslation members 96 are thus rotated with the gear disks 80 a, 80 bas they rotate. The exterior surfaces 136 of the lateral rollers 132provide a somewhat continuous surface that simulates the travel surfaceof a conventional motorcycle tire. In this mode, the motors 56 a, 56 bcan be operated to rotate the gear disks 80 a, 80 b at the same angularspeed in either a first angular (forward rotational) direction, causingthe rear wheel 40 to rotate to drive the toy motorcycle 20 forward, orin a second angular (backward rotational) direction, causing the rearwheel 40 to rotate to drive the toy motorcycle 20 backward.

The motors 56 a, 56 b can also be operated to rotate the first gear disk80 a at a different angular velocity than the second gear disk 80 babout the rear axle 68. That is, at least one of the angular speed andthe angular direction of rotation of the first gear disk 80 a differsfrom that of the second gear disk 80 b. The difference in angularvelocity between the gear disks 80 a, 80 b causes the gear faces 84 a,84 b of the gear disks 80 a, 80 b to rotate relative to one another. Asthe gear disks 80 a, 80 b rotate relative to one another, the gear faces84 a, 84 b simultaneously rotate all of the frustoconical gears 100 ofthe transmission translation members 96. The transmission translationmembers 96 rotate about their rotation axes at a rate that isproportional to the difference in the angular velocities of the geardisks 80 a, 80 b.

The transmission translation members 96 and the lateral rollers 132 actas peripheral translation assemblies to transfer torque applied by thegear disks 80 a, 80 b to the lateral rollers 132 to cause rotation ofthe lateral rollers 132. As the transmission translation members 96rotate, engagement of the edge of the rotating peripheral gear faces 104with the circumferential recess patterns 140 on the lateral rollers 32causes the lateral rollers 132 to rotate according to the rotationaldirection and speed of the transmission translation members 96, therebytranslating the torque of the transmission translation members 96 abouttheir rotation axes transmitted to the lateral rollers 132. Further, thesupport frame portions 88 a, 88 b and the transmission translationmembers 96 positioned therebetween rotate about the rear axle 68 at anangular velocity that is the average of the angular velocities of thegear disks 80 a, 80 b.

FIG. 7 shows the toy motorcycle 20 positioned on a travel surface 224.The rear wheel 40 of the toy motorcycle 20 can be operated to drive therear wheel 40 relative to the travel surface 224 in a forward directionRF or a backward direction RB, and, simultaneously, in a left directionRL or a right direction RR, as will be discussed below.

FIG. 8 shows various physical and/or logical components of the toymotorcycle 20 that act to control its movement. A control module 228 iscoupled to a battery unit 232, to the left rear wheel control motor 56 acontrolling rotation of the first gear disk 80 a, to the right rearwheel control motor 56 b controlling rotation of the second gear disk 80b, and to a front wheel steering motor 242. The left rear wheel controlmotor 56 a and the right rear wheel control motor 56 b may, forsimplicity, be referred to simply as the left motor 56 a and the rightmotor 56 b respectively. The front wheel steering motor 242 controlspivoting of the forks 32 and, thus, the front wheel 28. A set of sensors248 are coupled to the control module 228. The sensors 248 includeorientation sensors for determining the orientation of the toymotorcycle 20 and an inertial measurement unit (“IMU”) for determiningits acceleration. The battery unit 232 includes one or more batteriesfor powering the left motor 56 a and the right motor 56 b, as well asthe control module 228 and the sensors 248. The control module 228controls the direction of rotation of each motor 56 a, 56 b, as well asits speed of rotation. In doing so, the control module 228 controls thepower supplied by the battery unit 232. An RF receiver 252 is coupled tothe control module 228 for receiving operation commands via radiofrequency signals sent by a remote control unit 256.

As shown, the remote control unit 256 has a set of user controls,including a steering wheel 260, a joystick 264, and a wheelie button268. In response to user interaction with the controls, the remotecontrol unit 256 generates operation commands, such as “turn left xunits”, “drive forward with y speed units and drive left with z speedunits” (where the units are interpreted by the control module 228), and“perform a wheelie”. While the remote control unit 256 in thisembodiment communicates operational commands via radio frequency, theremote control unit 256 may communicate with the toy motorcycle 20 viawired communications, Bluetooth, or any other suitable means in otherembodiments.

FIG. 9 shows a steering assembly 272 of the toy motorcycle 20. Thesteering assembly 272 includes the front wheel steering motor 242 thatis controlled by operation commands in the form of steering commandsgenerated by the remote control unit 256 (FIG. 8) as a result of turningthe steering wheel 260. Two rigid steering rods 280 (FIG. 9) arepivotally coupled to laterally opposite ends of a motor output member284 that is driven by the front wheel steering motor 242. The steeringrods 280 are pivotally coupled to opposite sides of the head assembly32, so that pivoting of the motor output member 284 by the front wheelsteering motor 242 in a first or second direction pivots the headassembly 32 (in the first or second direction) and thus the front wheel28 (FIG. 7). A centering spring 287 is optionally provided so that whenthe steering wheel 260 (FIG. 8) is released by the user, the front wheelsteering motor 242 may be de-powered, and the centering spring 287 (FIG.9) returns the head assembly 32 back to a home position in which thefront wheel 28 (FIG. 7) is pointed directly forward.

Now with reference to FIGS. 7, 8, and 10, the joystick 264 is biased toreturn to a center position C when not urged in another direction. Thejoystick 264 has two degrees of movement. When the joystick 264 ispivoted away from the center position C, the remote control unit 256transmits operation commands in the form of drive commands to the toymotorcycle 20 to control operation of the motors of the toy motorcycle20 (not shown, but similar in design and operation to the motors 56 a,56 b of the toy motorcycle 20 of FIG. 1) coupled to the two gear disks80 a, 80 b. Pivoting of the joystick 264 in a forward direction 288 or abackward direction 290 controls the average rotation speed of the geardisks 80 a. Similarly, pivoting of the joystick 264 in a left direction292 or a right direction 294 controls the difference in rotation speedof the gear disks 80 a. The joystick 264 can move away from center bothin the forward direction 288 or the backward direction 290 and in theleft direction 292 or the right direction 294 simultaneously to drivethe rear wheel 40 simultaneously forward or backward, and left or right.Pivoting of the joystick 264 in the forward direction 288 or thebackward direction 290 away from the center position C is resisted lessthan movement of the joystick 264 in the left direction 292 or the rightdirection 294 away from center in order to require a conscious effort ofthe user to cause lateral movement and to avoid accidental lateralmovement.

FIG. 10 shows the mappings between positions of the joystick 264 and therotation directions of the gear disks 80 a, 80 b as shown in FIGS. 11Ato 11D.

FIGS. 11A to 11D are rear views of the rear wheel 40 illustrating itsoperation, wherein both gear disks 80 a rotate in a forward rotationaldirection (i.e., the rotational direction of the rear wheel 40 to drivethe rear wheel 40 forward across a surface), both rotate in a backwardrotational direction (i.e., the direction of rotation of a wheel to movea vehicle backward), the first gear disk 80 a rotates in a forwardrotational direction and the second gear disk 80 b rotates in a backwardrotational direction, and the first gear disk 80 a rotates in a backwardrotational direction and the second gear disk 80 b rotates in a forwardrotational direction.

The angular velocity of the rear peripheries of the first gear disk 80 aand the second gear disk 80 b are illustrated as v₁ and v₂ respectively.Movement of the rear wheel 40 in the forward direction RF or thebackward direction RB is determined by the average angular velocity ofthe gear disks 80 a, 80 b, as the lateral rollers 132 that contact thetravel surface 224 to provide the ground contact surface of the rearwheel 40 rotate about the rear axle 68 at the average angular velocityof the gear disks 80 a, 80 b. If the average angular velocity (that is,the average of v₁ and v₂) represents rotation of the rear wheel 40 in aforward rotational direction (that is, the rotational direction of therear wheel 40 to drive the rear wheel 40 forward across a surface), thenthe rear wheel 40 moves at least partially in a forward direction RF.Alternatively, if the average angular velocity represents rotation ofthe rear wheel 40 in a backward rotation direction (that is, therotational direction of the rear wheel 40 to drive the rear wheel 40backward across a surface), then the rear wheel 40 moves at leastpartially in a backward direction RB. The speed at which the rear wheel40 moves in a forward direction RF or a backward direction RB isproportional to the speed component of the average angular velocity ofthe gear disks 80 a, 80 b. If the average angular velocity is zero, thenthe toy motorcycle 20 is neither driven forward or backward by the rearwheel 40.

Similarly, movement of the rear wheel 40 in the left direction RL or theright direction RR is determined by the difference in the angularvelocities v₁ and v₂ of the gear disks 80 a, 80 b. If the angularvelocities v₁ and v₂ are equal, then the rear wheel 40 is not drivenlaterally. If, instead, the angular velocities v₁ and v₂ are not equal,then the lateral rollers 132 also rotate about axes that are orthogonalto the rotational axis RA of the rear wheel 40 to also drive the rearwheel 40 laterally. In particular, if v₁ is greater in the forwardrotational direction than v₂, then the lateral rollers 132 rotate totranslate the rear wheel 40 in the left direction RL at a speed relativeto the difference between v₁ and v₂. Conversely, if v₁ is less than v₂in a forward rotational direction, then the lateral rollers 132 rotateto translate the rear wheel 40 in the right direction RR at a speedrelative to the difference between v₁ and v₂.

Generally, the driving force of the rear wheel 40 across the travelsurface 224 is a combination of the driving force along the forwarddirection RF or backward direction RB as a result of the average angularvelocity of the gear disks 80 a, 80 b, and the driving force along theleft direction RL or the right direction RR as a result of thedifference in the angular velocity of the gear disks 80 a, 80 b. Thus,the rear wheel 40 can drive in the forward or backward direction RF thatis orthogonal to the rotation axis RA of the rear wheel 40, in a rightdirection RR or a left direction RL that is parallel to the rotationaxis RA of the rear wheel 40, and in another direction that is acombination of the forward direction RF or the backward direction RB,and the right direction RR or the left direction RL and, thus, obliqueto the rotation axis RA of the rear wheel 40.

FIG. 11A shows the rear peripheries of the two gear disks 80 a rotatingin a forward rotational direction at angular velocities v₁ and v₂respectively. As the average angular velocity will be in the forwardrotational direction, the rear wheel 40 will drive in the forwarddirection RF across the travel surface 224. The rear wheel 40 may alsosimultaneously drive laterally, depending upon the difference between v₁and v₂.

FIG. 11B shows the rear peripheries of the two gear disks 80 a rotatingin a backward rotational direction at angular velocities v₁ and v₂respectively. As the average angular velocity will be in the backwardrotational direction, the rear wheel 40 will drive in the backwarddirection RB across the travel surface 224. The rear wheel 40 may alsosimultaneously drive laterally, depending upon the difference between v₁and v₂.

FIG. 11C shows the rear periphery of the first gear disk 80 a rotatingin a forward rotational direction at angular velocity v₁ and the rearperiphery of the second gear disk 80 b rotating in a backward rotationaldirection at angular velocity v₂. If the average angular velocity (thatis, the average of v₁ and v₂) represents rotation of the rear wheel 40in a forward rotational direction, then the rear wheel 40 drives in aforward direction RF. Alternatively, if the average angular velocityrepresents rotation of the rear wheel 40 in a backward rotationdirection, then the rear wheel 40 drives in a backward direction RB. Thespeed at which the rear wheel 40 drives in a forward direction RF or abackward direction RB is proportional to the speed component of theaverage angular velocity of the gear disks 80 a, 80 b. Additionally, therear wheel 40 also simultaneously drives laterally in a directiondetermined by the difference between v₁ and v₂ at a speed proportionalto the difference between v₁ and v₂.

FIG. 11D shows the rear periphery of the first gear disk 80 a rotatingin a backward rotational direction at angular velocity v₁ and the secondgear disk 80 b rotating in a forward rotational direction at angularvelocity v₂. If the average angular velocity represents rotation of therear wheel 40 in a forward rotational direction, then the rear wheel 40drives in a forward direction RF. Alternatively, if the average angularvelocity represents rotation of the rear wheel 40 in a backward rotationdirection, then the rear wheel 40 drives in a backward direction RB. Thespeed at which the rear wheel 40 drives in a forward direction RF or abackward direction RB is proportional to the speed component of theaverage angular velocity of the gear disks 80 a, 80 b. Additionally, therear wheel 40 also simultaneously drives laterally in a directiondetermined by the difference between v₁ and v₂ at a speed proportionalto the difference between v₁ and v₂.

Referring now to FIGS. 7 to 11D, using the remote control unit 256, auser can direct the toy motorcycle 20, when turned on and in an uprightposition atop of a travel surface, to perform various maneuvers, such astravelling forwards or backwards in a straight line by pivoting thejoystick 264 in the forward direction 288 or the backward direction 290.

The toy motorcycle 20 is self-balancing in an upright orientation viacontrol of the rear wheel control motors 56 a, 56 b and the front wheelsteering motor 242 by the control module 228. The control module 228receives orientation and acceleration data from the sensors 248, as wellas the drive commands received from the remote control unit 256, anddetermines how to control operation of the composite rear wheel 40 andthe front wheel steering motor 242 controlling pivoting of the frontwheel 28 to maintain the toy motorcycle 20 upright. The composite rearwheel 40 can be controlled to drive backwards or forwards, andsimultaneously left or right by independent operation of the gear disks80 a, 80 b, and the front wheel 28 can be operated to pivot to maintainthe center-of-gravity generally over the area of contact between thefront wheel 28, the rear wheel 40, and the travel surface 224.

When the toy motorcycle 20 is turned on, allowed to calibrate, andplaced upright atop of a travel surface, the control module 228 receivesorientation and acceleration data from the sensors 248 and, in response,determines how to modify control of the left motor 56 a, the right motor56 b, and the front wheel steering motor 242 to maintain thecenter-of-gravity of the toy motorcycle 20 over the area of contact ofthe wheels 28, 40 with the travel surface 224. This can includemodifying or ignoring the operational commands received from the remotecontrol unit 256.

FIG. 12 shows operation of the toy motorcycle 20 so that the toymotorcycle 20 appears to be making a series of alternating turns in ans-shaped pattern. The toy motorcycle 20 can travel forwards or backwardsalong an s-shaped path by steering the front wheel 28 via the steeringwheel 260 of the remote control unit 256 while pivoting the joystick 264in the forward direction 288 or the backward direction 290 respectively.

This general maneuver can also be achieved by maintaining the frontwheel straight (by not turning the steering wheel 260 on the remotecontrol unit 256) and by alternating the joystick 264 between left andright of center C while the joystick 264 is urged in the forwarddirection 288 or the backward direction 290. This causes the rear wheel40 to swing around alternatingly. Thus, as the rear wheel 40 is capableof lateral movement, front wheel steering can be mimicked.

FIG. 13 shows the toy motorcycle 20 rotating about the front wheel 28 byoperation of the rear wheel 40 in such a manner that the average angularvelocity of the gear disks 80 a, 80 b is zero, but the left gear disk 80a is rotated in a forward rotational direction and the right gear disk80 b is rotated in a backward rotational direction, as shown in FIG.11C.

FIG. 14 shows the toy motorcycle 20 being operated to simulate“drifting” or controlled oversteer by steering the front wheel 28 in onedirection MF (i.e., left or right) and causing the rear wheel 40 to moveboth forward and in the same direction in which the front wheel 28 isbeing steered using the joystick 264. As a result, the rear wheel 40 ismoved in a direction DD that is oblique to the rotation axis RA of therear wheel 40.

FIG. 15 illustrates the toy motorcycle 20 performing a “wheelie”,wherein the toy motorcycle 20 is reoriented to travel upon the rearwheel 40 only. This is achieved by actuating the wheelie button 268 ofthe remote control unit 256. Upon actuation of the wheelie button 264,the control module, upon receiving an operational command in the form ofa wheelie command generated by the remote control unit 256, controls themotors 56 a, 56 b to cause the toy motorcycle 20 to accelerate straightbackwards for a set time or until a minimum speed is reached, and thenaccelerate quickly forwards. The inertia of the upper portion of the toymotorcycle 20 resists the forward acceleration and the toy motorcycle 20is reoriented so that the toy motorcycle 20 is balancing on the rearwheel 40 only (i.e., performs a wheelie). The control module 228determines how to control the motors 56 a, 56 b to maintain thecenter-of-gravity of the toy motorcycle 20 over the area of contact ofthe front wheel 28 and the rear wheel 40 with the travel surface 224. Asthere is no contact of the front wheel 28 with the travel surface 224 inthis orientation, the control module 228 maintains the center-of-gravityof the toy motorcycle 20 over the area of contact of the rear wheel 40with the travel surface 224. The rear wheel 40 can move in a forwarddirection RF or a backward direction RB, and in a left direction RL or aright direction RR, or any combination of a forward direction RF or abackward direction RB, and in a left direction RL or a right directionRR in order to maintain the center-of-gravity over the area of contactof the rear wheel 40 with the travel surface 224.

Alternatively, a user could employ the joystick 264 to perform the samesequence of actions without actuating the wheelie button 268. Stillfurther, the toy motorcycle 20 could be placed on a surface such thatthe toy motorcycle 20 is generally in a wheelie orientation (that is,with its center-of-gravity positioned over the area of contact of itsrear wheel 40 with the travel surface 224), and the control module 228can recognize its orientation and control the motors 56 a, 56 b and thefront wheel steering motor 242 to maintain this orientation. In thiscase, the control module 228 may recognize the wheelie orientation (thatis, the orientation of the toy motorcycle 20 when the center-of-gravityis above the area of contact of the rear wheel 40 with the travelsurface) and control the rear wheel 40 (and the pivoting of the frontwheel, in some cases) to maintain the center-of-gravity over the area ofcontact of the rear wheel 40 with the travel surface.

Referring now to FIGS. 7 to 15, during the performance of all of thesemaneuvers, the control module 228 continually processes the orientationand acceleration information from the sensors 248 and determines how tomaintain the center-of-gravity over the area of contact of the wheels28, 40 with the travel surface 224 by adjusting the operation of theleft and right motors 56 a, 56 b controlling the composite rear wheel40, and operation of the front wheel steering motor 242 controlling thepivoting of the front wheel 28. As a result, the two-wheeled toymotorcycle 20 is able to maintain itself upright where the toymotorcycle 20 would otherwise tip over.

FIGS. 16 and 17 show a composite rear wheel 300 of a toy motorcycle inaccordance with another embodiment. The composite rear wheel 300 has anexterior shell 304 similar to the shell of the rear wheel 40 formed bythe shell portions 116 of the toy motorcycle 20 of FIGS. 1 to 6, with afew exceptions. The exterior shell 304 is driven via a drive interfacein the form of a non-round drive recess 308 on a first side, and has ahub 312 with a fixed orientation therein. The hub 312 has a plurality ofradial axles 316 atop of which are freely rotatably mounted a set oftransmission translation members 320. Secured to the inside the exteriorshell 304 are positioning rings 324 that have a set of apertures inwhich necks 328 of the transmission translation members 320 are secured.Each of the transmission translation members 320 has a peripheral gearface 332 that turns a lateral roller 336 on a roller axle 338 in asimilar manner as in the embodiment illustrated in FIGS. 1 to 7. Thelateral rollers 336 are at fixed positions relative to the exteriorshell 304.

A gear disk 340 is freely rotatably positioned within the exterior shell304, and has a projection bracket 344 that extends through a roundaperture in a second side of the exterior shell 304. The projectionbracket 344 has a drive interface in the form of a non-round driverecess 348 for driving the gear disk 340. The gear disk 340 has atoothed gear face 352 that engages a frustoconical gear 356 of thetransmission translation member 320.

The hub 312 and the gear disk 340 are freely rotatably mounted on a rearaxle 360 that is secured to a rear wheel support 364. A first drivearrangement 368 a includes a motor (hidden) and is coupled to the geardisk 340 to drive the gear disk 340. A second drive arrangement 368 bincludes a motor 372 and is coupled to the exterior shell 304 to drivethe exterior shell 304. The second drive arrangement 368 b drivesrotation of the rear wheel 300 and thus the set of lateral rollers 336about the rotation axis RA of the rear wheel 300.

If the gear disk 340 is rotated with the same angular velocity as theexterior shell 304, then the toothed gear face 352 does not moverelative to the frustoconical gears 356 of the transmission translationmembers 320. As a result, the lateral rollers 336 do not rotate aboutthe roller axles 338 to drive the rear wheel 300 laterally. If, instead,the gear disk 340 is rotated at a different angular velocity than is theexterior shell 304, then the toothed gear face 352 rotates relative tothe frustoconical gears 356 of the transmission translation members 320,causing them to rotate about the roller axles 338 to drive the rearwheel laterally. Thus, from a drive arrangement perspective, the rearwheel 300 is driven in generally the same manner as is the rear wheel 40of the toy motorcycle 20 of FIGS. 1 to 6 and the rear wheel 40 of thetoy motorcycle 20 of FIG. 7, with the exception that greater forwardangular velocity applied by the first drive arrangement 368 a to thegear disk 340 relative to the angular velocity of the second drivearrangement 368 b to the exterior shell 304 results in lateral movementin a right direction RR.

In an alternative embodiment, a toy motorcycle similar to the toymotorcycle 20 of FIGS. 1 to 15 may be provided that does not have asteering mechanism to control of the orientation of the front wheel,like the toy motorcycle of FIGS. 1 to 15. That is, the front wheel ofthe toy motorcycle in this alternative embodiment is in a fixedorientation relative to the body thereof. The toy motorcycle withoutfront wheel orientation control can maintain its center-of-gravitypositioned over the area of contact between the front and rear wheelsand a travel surface solely through control of its motors (similar tomotors 56 a, 56 b of the toy motorcycle 20 of FIGS. 1 to 15) thatoperate its composite rear wheel. The toy motorcycle in this alternativeembodiment is capable of performing all of the same maneuvers as the toymotorcycle 20 of FIGS. 1 to 15, but may not possess the stability of thetoy motorcycle 20 while simulating a drifting maneuver as its frontwheel is in a fixed orientation.

In some embodiments, the sensors of the self-balancing two-wheeledvehicle can only determine orientation and the control module candetermine how to control the motors driving the rear wheel and the frontwheel steering motor only using orientation data.

The front wheel may also be constructed and controlled like the rearwheel.

A single continuous lateral roller that is rotatable can be used inplace of multiple lateral rollers. In this case, the axis about whichthe single continuous lateral roller rotates is a curved axis that isgenerally at each point orthogonal to a rotation axis of the secondwheel.

While it has been shown that the rear wheel includes one or more lateralrollers and is controlled by at least one rear wheel control motor, andthat the front wheel is optionally steerable via a front wheel steeringmotor, it is alternatively possible for the self-balancing vehicle tohave a different structure, wherein the rear wheel is pivotable and iscontrolled by a rear wheel steering motor and for the front wheel toinclude the lateral rollers which are driven by at least one front wheelcontrol motor. Thus, the wheel that steers via pivoting need not be thefront wheel, and may be referred to as a first wheel, and the otherwheel, which includes lateral rollers, may be referred to as a secondwheel. Similarly the front wheel steering motor may be referred to as afirst wheel steering motor, and similarly the at least one rear wheelcontrol motor (e.g. the first and second rear wheel control motors) maybe referred to as at least one second wheel control motor or at leastone motor coupled to the second wheel.

Persons skilled in the art will appreciate that there are yet morealternative implementations and modifications possible, and that theabove examples are only illustrations of one or more implementations.The scope, therefore, is only to be limited by the claims appendedhereto.

What is claimed is:
 1. A self-balancing two-wheeled vehicle, comprising: a body; a first wheel rotatably coupled to the body; a second wheel rotatably coupled to the body, the second wheel having at least one lateral roller rotatable about a roller axis that is one of oblique and orthogonal to a rotation axis of the second wheel; at least one motor coupled to the second wheel to control rotation of the second wheel and the at least one lateral roller; at least one sensor coupled to the body to generate orientation data therefor; a control module coupled to the at least one sensor and the at least one motor to control operation thereof at least partially based on the orientation data generated by the at least one sensor; and a receiver coupled to the control module to communicate operational commands received from a remote control unit to the control module, the remote control unit having a set of user controls and communicating the operational commands generated by actuation of the user controls, wherein the control module at least partially controls the at least one motor at least partially based on the operational commands to maintain a center-of-gravity of the self-balancing two-wheeled vehicle over an area of contact of the first wheel and the second wheel with a travel surface, and wherein the first wheel is pivotable relative to the body, and wherein pivoting of the first wheel is controlled by the control module at least partially based on the operational commands received from the remote control unit.
 2. A self-balancing two-wheeled vehicle as claimed in claim 1, wherein the second wheel has a first drive interface and a second drive interface to which the at least one motor is coupled, the first drive interface being rotatable independent of the second drive interface.
 3. A self-balancing two-wheeled vehicle as claimed in claim 2, wherein a first of the at least one motor is coupled to the first drive interface and a second of the at least one motor is coupled to the second drive interface.
 4. A self-balancing two-wheeled vehicle as claimed in claim 3, wherein the second wheel has a plurality of lateral rollers.
 5. A self-balancing two-wheeled vehicle as claimed in claim 4, wherein rotation of the lateral rollers is at least partially based on a difference in angular velocity of the first drive interface and the second drive interface.
 6. A self-balancing two-wheeled vehicle as claimed in claim 5, wherein each lateral roller is rotated by a transmission translation member engaged by at least one gear, each of the at least one gear being rotated via one of the first drive interface and the second drive interface.
 7. A self-balancing two-wheeled vehicle as claimed in claim 6, wherein a first of the at least one gear is rotated via the first drive interface and a second of the at least one gear is rotated via the second drive interface.
 8. A self-balancing two-wheeled vehicle as claimed in claim 2, wherein the first drive interface fully controls rotation of the second wheel about a rear axle.
 9. A self-balancing two-wheeled vehicle as claimed in claim 1, wherein the at least one sensor includes an accelerometer that generates acceleration data, and wherein the control module controls operation of the at least one motor at least partially based on the accelerometer data received from the accelerometer.
 10. A self-balancing two-wheeled vehicle as claimed in claim 1, wherein pivoting of the first wheel is at least partially controlled by the control module to maintain the center-of-gravity of the self-balancing two-wheeled vehicle over the area of contact of the first wheel and the second wheel with the travel surface.
 11. A self-balancing two-wheeled vehicle, comprising: a body; a first wheel rotatably coupled to the body; a second wheel rotatably coupled to the body, the second wheel having at least one lateral roller rotatable about a roller axis that is one of oblique and orthogonal to a rotation axis of the second wheel; at least one motor coupled to the second wheel to control rotation of the second wheel and the at least one lateral roller; at least one sensor coupled to the body to generate orientation data therefor; a control module coupled to the at least one sensor and the at least one motor to control operation thereof at least partially based on the orientation data generated by the at least one sensor; and a receiver coupled to the control module to communicate operational commands received from a remote control unit to the control module, the remote control unit having a set of user controls and communicating the operational commands generated by actuation of the user controls, wherein the control module at least partially controls the at least one motor at least partially based on the operational commands to maintain a center-of-gravity of the self-balancing two-wheeled vehicle over an area of contact of the first wheel and the second wheel with a travel surface, and wherein the operational commands comprises a wheelie command, and wherein the remote control unit, upon receiving the wheelie command from the remote control unit, controls the second wheel to accelerate in a first direction away from the first wheel and immediately subsequently accelerate in a second direction towards the front wheel to reorient the self-balancing two-wheeled vehicle so that the center-of-gravity of the self-balancing two-wheeled vehicle is over the area of contact of the second wheel with the travel surface, wherein the control module controls the at least one motor at least partially to maintain the center-of-gravity of the self-balancing two-wheeled vehicle is over the area of contact of the second wheel with the travel surface. 